1. Technical Field
The present invention relates to a system for controlling the displacement of carriage working machine in a spinning mill wherein a plurality of spinning frames or roving frames are installed, this working machine being capable of traveling along end of respective groups of these spinning machines, while an automatic apparatus for carrying out a certain part of the process performed with these spinning machines is rigidly or detachably mounted thereon.
2. Description of the Related Art
In so-called modern spinning mills, automatic systems are used to realize, for example, a rational processing together with a reduction in labor costs, an increased production speed, and an up-grading of production efficiency, and it is well known that in a processing system utilizing automatic doffing for spinning machines such as roving frames or spinning frames, a processing system for automatically replacing exhausted roving bobbins with halfway exhausted roving bobbins, or for automatically replacing exhausted roving bobbins with full packaged roving bobbins respectively in spinning frames, is used. For example, an automatic doffing system is applied to the roving process (as shown in EP-A2-0148129) and also in the spinning process (as shown in US-A-4145868), an automatic system for replacing almost exhausted roving bobbins mounted on the respective back creels with the halfway exhausted roving bobbins mounted on the respective back creels of each side of the spinning frame, have been applied in recent years (as shown in US-A-4473997). The above-mentioned replacing of roving bobbins is hereinafter called "automatic switching". In such automatic doffing and automatic switching systems, it is usual to use a carriage which is capable of carrying a pair of automatic doffing apparatuses or automatic switching apparatuses to a position adjacent to an end of a spinning machine to which the operation of these automatic apparatuses is to be applied. However, this direction along the track thereof, and when a change in the travel direction at each terminal of this track becomes necessary, several problems including that of working efficiency must be solved under the present circumstances.
Another automatic system modified from the above-mentioned automatic doffing or switching system can be utilized in the spinning mill, that is, the automatic doffing apparatus or switching apparatus is built-in the above-mentioned carriage as one body. However, in this system, the automatic doffing apparatus is displaced together with the carriage along the spinning machine when the carriage is displaced to a position on the track adjacent to the end of the abovementioned spinning machine. In this modified system, the problem of the above-mentioned first sytem cannot be avoided.
The above-mentioned problems are hereinafter explained in more detail by a typical example of the automatic doffing system applied for a group of spinning frames.
As is well known, the operation of these spinning frames and the displacement of the carriage are absolutely independent, and the travel direction of the carriage can be changed at only both terminal ends of the travel path along this group of spinning frames.
For example, in the automatic doffing system applied to the spinning system disclosed in U.S. Pat. No. 4,145,868, since the automatic doffing apparatus, mounted on the carriage, must start the doffing operation after the carriage is displaced to a position adjacent to a spinning frame which has issued a signal requesting the doffing operation during the displacement of the carriage in one direction along a track laid adjacently along ends of the spinning frames, if the above-mentioned spinning frame is located at a downstream position which the carriage has passed on the track facing this spinning frame, the distance for displacing the carriage to the above-mentioned position on the track facing the spinning frame which is requesting the doffing operation becomes excessively large, because the travel direction of the carriage can only be changed at both end terminals of the track. In other words, the time needed to displace the carriage to the above-mentioned spinning machine becomes excessively long, so that it is impossible to avoid a delay in the starting time of the doffing operation of the above-mentioned spinning frame. Such a delayed operation of the doffing apparatus lowers the entire working efficiency of the automatic doffing system in the spinning room. Accordingly, this is the first problem to be solved.
Recently, there is a tendency whereby, in a group of spinning frames, several different types of spinning yarns having different yarn counts are simultaneously produced by the respective spinning frames, i.e., a system of simultaneously producing several yarns of different types on a small production scale is carried out. In such a condition, it is essential to start the doffing operation from a spinning frame taking a position at one side of the alignment of the spinning frames in the group, then at the next spinning frame taking a position adjacent to the above-mentioned first spinning frame, and then to the next spinning frame taking a position adjacent to the above-mentioned second spinning frame and so on. Accordingly, to avoid possible interference between doffing operations among these spinning frames, the package sizes of cops are stepwisely changed with respect to the spinning frames, so as to issue signals requesting a doffing operation in an order such that the doffing operation of a spinning frame can be started after the completion of the doffing operations of another spinning frame located at an adjacent upstream position with respect to the track of the working machine. However, in such a condition, it is necessary to determine the package size of cops in a condition smaller than the full package size. Therefore, inevitably, the number of doffing operations needed to carry out the operation of the group of spinning frames must be increased; in other words, the production efficiency of the group of spinning frames is lowered. This is the second serious problem of the conventional doffing system.
To solve this problem, the following system can be considered whereby the doffing operations of such spinning frames as a spinning frame producing coarse yarn, which needs comparative many doffing operations, may be carried out in order of priority. However, if the carriage provided with a doffing apparatus which can only change its travel direction at both terminal ends of the displacing track thereof is used, the timing for changing the travel directions is very restricted and thus such a doffing system is not practical. This is the third problem to be solved.
In addition to the above-mentioned problems the following problems have been recognized as serious. That is, in the conventional system, the working machine to operate the automatic doffing operation or switching operation is stopped by detecting a lit call lamp disposed in the end portion of each spinning frame, and then must wait for the switch ON of an indication lamp which indicates that the size of the product package has becomes full. Therefore, if such an indication lamp is broken or burned-out, or the ring rail of a spinning frame does not fall down to a position which is necessary to carry out the doffing operation, because of improper driving of this spinning frame, or it cannot be confirmed that the automatic apparatus is ready to carry out the operation because the ring rail does not fall down, or it is impossible to confirm whether or not the above-mentioned call lamp is lit, the carriage holding the automatic apparatus is thus forced to remain continuously at a position adjacent to the end of the spinning frame, and the efficiency of the operation of the automatic apparatus is lowered.
Like the above-mentioned doffing operation of the spinning frame, it is practical to use the carriage holding the automatic apparatus to carry out the doffing operation for roving frames. Therefore, in the roving process, problems similar to the above-mentioned problem in the doffing operation of the spinning frames must be confronted.
In the modified system utilizing such an automatic doffing or switching apparatus secured to the carriage, the same problem as in the above-mentioned system utilizing the automatic doffing or switching apparatus detectably mounted on the carriage cannot be avoided.
Accordingly, hereinafter for brevity, the roving frame and the spinning frame are referred to by one term "spinning machine", which means either one or both of the roving frame and the spinning frame, and the term "carriage working machine" is used to cover all the embodiments such as the above-mentioned carriage which functions to carry the automatic doffing apparatus or automatic switching apparatus, the above-mentioned automatic machine constructed as a carriage and the automatic doffing or switching apparatus rigidly mounted on this carriage.